1. Technical Field
The present invention relates to a radiographic imaging device and to an image processing device.
2. Related Art
Recently radiation detectors of FPD's (Flat Panel Detectors) etc. that can directly convert radiation into digital data have been put into practice, the FPD's having a radiation sensitive layer disposed on a TFT (Thin Film Transistor) active matrix substrate. Portable radiographic imaging devices (referred to below as “electronic cassettes”) have also recently been put into practice using such FPD's or the like, the portable imaging devices generating image data representing radiographic images of radiation irradiated thereon, and storing the generated image data.
However, in such FPD's, charge is generated and accumulated in each pixel even in a state in which X-rays are not irradiated, due to dark current etc. Consequently, an accumulation extraction operation is performed repeatedly in the electronic cassette during standby to extract and remove any charge accumulated in each of the pixels of the FPD. If this accumulation extraction operation is stopped midway then a line aberration is generated in the radiographic image at the position at which the extraction operation of the reset mode was stopped, with a reduction in image quality. Therefore, in order to suppress such reduction in image quality it is necessary to wait until one frame's worth the accumulation extraction operation has been completed, with this sometimes generating a time lag till commencement of imaging.
As a technique to shorten such a time lag, a technique is described in Japanese Patent Application Laid-Open (JP-A) No. 2005-13272 in which synchronization of the accumulation extraction operation and X-ray generation timing becomes unnecessary by notifying the drive state (accumulation extraction operation) of a FPD to the person who is doing the imaging.
Also, in JP-A No. 2005-46203, by instructing X-ray imaging preparation X-ray generation preparation is performed to the X-ray source, and imaging preparation is performed in the FPD, with charge accumulation commenced a specific duration after completion of imaging preparation. When imaging is instructed within the specific duration, X-rays are irradiated from the X-ray source, and charge accumulation is ended when a specific duration has passed from commencing charge accumulation, and charge extraction is performed from each of the pixels of the FPD.
However, in the techniques of JP-A No. 2005-13272 and JP-A No. 2005-46203 suffer from the problem that the imaging timing is limited, and there are occasions when a radiographic image cannot be captured at a specific timing.
Namely, in the technique of JP-A No. 2005-13272, imaging can only be performed at a timing in accordance with the notified drive state of the FPD, and the imaging timing is limited.
In the technique of JP-A No. 2005-46203, imaging must be instructed and X-rays irradiated from the X-ray source from commencing charge accumulation of the FPD until a specific duration has elapsed, and if the specific duration is exceeded then X-ray imaging preparation must be started over again, limiting the imaging timing.